1. Field of the Invention
The present invention relates to communication systems. In particular, the present invention relates to unified communications among communication devices.
2. Description of the Background Art
Existing communication systems provide numerous services to numerous different clients. These services include, for example, telephony calls, voicemail, directory, etc. A first problem present in existing communication systems is that the clients must communicate with different interfaces in order to access the different services provided by the communication system. For example, an internet protocol phone accesses a different interface than a personal computer with a web browser, and both of these devices access a different interface than a mobile phone. Not only is this inconvenient for the user of the client, it also means the user must learn to use different interfaces.
A second problem present in existing systems is that the services offered by these systems cannot be easily opened up to third party developers that can provide new and innovative services for clients.
A third problem present in existing systems is that they do not support a subscription model that allows clients to subscribe to services offered by the communication system. For example, a user of a communication device cannot subscribe with the communication system to receive updates regarding the presence of another user on the network.
A fourth problem present in existing systems is that they are not able to allow an administrator to add, modify and delete permissions for other clients and/or client devices and to provide clients with error messages when they do not have permission to receive a requested service.